1. Field of the Invention
The present invention relates to hydraulic controls for injection molding machines, and in particular to arrangements of hydraulic controls and hydraulic components on the base of an injection molding machine.
2. Description of the Prior Art
Injection molding machines require a number of hydraulic control components for the operation of the die closing unit, injection unit or units, parts ejection device, core removing unit, etc. These hydraulic controls are normally arranged in accordance with design expedience or availability of mounting space. In a known machine base of this type, as disclosed in my U.S. Pat. No. 3,914,082, a number of hydraulic distributors are combined in a compact distributor block which is mounted in a horizontal position inside the forward compartment of the machine base, at a level situated below the level of hydraulic fluid in the adjacent hydraulic fuel reservoir. The solenoid valves associated with the distributor block are attached to the underside of the distributors in a compact row. The oil filter for the hydraulic system, arranged in the return line, is likewise arranged below the fluid level of the reservoir.
In other prior art solutions, the various distributors are not combined in a single distributor block, but two or more groups of distributors are arranged at different locations on the machine base, in accordance with the position of the various machine components.
Among the shortcomings inherent to these prior art solutions are their lack of easy accessibility, poor cooling of the components, inadequate visibility of the components for visual inspection and monitoring, and frequently, poor placement of the adjustment knobs for the hydraulic controls. Lastly, the arrangement of a distributor system in several groups, or as a single block inside the machine base, is costly in terms of manufacture as well as in terms of servicing and replacement of components. For example, in the case of the distributor block situated below the fluid level, the latter has to be lowered, before the hydraulic controls components can be removed for inspection or replacement.